b3nj1, this is the "advanced" guide, this gets into GTL even and it's kinda only when you're an expert and really wanna push the envelope.
There is, I believe, an easier one before this one, posted long time ago.
Anyway, the process is the same, start raising FSB until voltages are not enough anymore, raise voltages a bit, repeat while voltages are safe. You can play it safe and only oc as far as your current voltage lets you go and don't overvolt.
This is a very simplistic aproach of course. You should have some margin at first so you can raise a bit at first, I guess if you go straight for 333 FSB you should manage to hold, try some stress test. If it's ok then start your way from there with smaller increments, like 5 or 10 MHz at a time a when you get to the limit try with even lower increments to reach the highest possible freq.
Go easy on it.